[olug] Split 7zip archives and restoring...

[Dan Linder]

I'm trying to backup my home directory to DVD.  I though I'd use 7-Zip
(available in most distributions).  It doesn't allow to write directly to
DVD so I have it create 50MB slices, and then once I get 4.4GB of slices, I
back them up.  The command I used is this:
  7z a -v50m /home/dan.backup/full-20080202.7z /home/dan/ -x!dan/Backups/*
This seemed to work for the backup -- my /home/dan.backup/ directory has
numerous "full-20080202.7z.###" (where ### starts at 001).

Before I reinstalled my system I wanted to test the backup files.  I thought
it would be something as simple as
1: "7z t full-20080202.7z.001" it reports "Testing full-20080202.7z.001" and
then "Everyting is Ok".
 - I know this is not true because I ran this against only the first three
pieces of a 200+ slice archive.
2: "7z l full-20080202.7z.001" (to see what files it has inside), It lists
the following:
   Date      Time    Attr         Size   Compressed  Name
------------------- ----- ------------ ------------
------------------------
2008-02-03 00:15:53        11933164371  11933164371  full-20080202.7z
------------------- ----- ------------ ------------
------------------------
                           11933164371  11933164371  1 files, 0 folders
3: Thinking that maybe I needed to use the original "full-20080202.7z" name,
I tried "7z t full-20080202.7z".  It reports "there is no such archive"
 - This makes sense since that file doesn't exist. :-)

4: I finally just tried this: "7z x -r full-20080202.7z.001" and I got a
large (but partial) file "full-20080202.7z".  (But it appears this file is
broken and 7z won't even test nor extract...)

The 7Zip documentation and website are quite lite on their notes on this.
Anyone else worked with 7z and splitting large archive files?

I started using "rar" but it was quite a bit slower than 7z and from what I
read it didn't handle things well if one of the archive slices was missing
or broken.

Dan

-- 
"Quis custodiet ipsos custodes?" (Who can watch the watchmen?) -- from the
Satires of Juvenal
"I do not fear computers, I fear the lack of them." -- Isaac Asimov (Author)
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